Abstract: An imaging sensor is configured to sense an environment through which a vehicle is moving. A method for controlling the imaging sensor includes receiving sensor data generated by the imaging sensor of the vehicle as the vehicle moves through the environment, determining (i) a lower bound for a vertical region of interest (VROI) within a vertical field of regard of the imaging sensor, the VROI comprising a virtual horizon, using a first subset of the sensor data, and (ii) an upper bound for the VROI within the vertical field of regard of the imaging sensor, using at least a second subset of the sensor data, where the first subset is smaller than the second subset. The method also includes causing the imaging sensor to be adjusted in accordance with the determined lower bound of the VROI and the determined upper bound of the VROI.

Abstract: A lidar system includes a light source, a scanner, and a receiver and is configured to detect remote targets located up to RMAX meters away. The receiver includes a detector with a field of view larger than the light-source field of view. The scanner causes the detector field of view to move relative to the instantaneous light-source field of view along the scan direction, so that (i) when a pulse of light is emitted, the instantaneous light-source field of view is approximately centered within the detector field of view, and (ii) when a scattered pulse of light returns from a target located RMAX meters away, the instantaneous light-source field of view is located near an edge of the field of view of the detector and is contained within the field of view of the detector.

Abstract: In one embodiment, a lidar system includes a light source configured to emit light at one or more wavelengths between 1200 nm and 1400 nm. The lidar system also includes a scanner configured to scan the emitted light across a field of regard of the lidar system and a receiver configured to detect a portion of the emitted light scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time for the portion of the emitted light to travel from the lidar system to the target and back to the lidar system.

Abstract: A system includes multiple sensors having different, and overlapping, fields of regard and a controller communicatively coupled to sensors. Methods for calibrating the multiple sensors include obtaining data from the sensors, determining optimized transformation parameters for at least one of the sensors, and transforming the data from one sensor projection plane to the other sensor projection plane. The method is an iterative process that uses the metric of mutual information between the data sets, and transformed data sets of the sensors, to determine an optimized set of transformation parameters. The sensors may be a plurality of lidar sensors, a camera and a lidar sensor, or other sets of sensors.

Abstract: A method for multi-object tracking includes receiving a sequence of images generated at respective times by one or more sensors configured to sense an environment through which objects are moving relative to the one or more sensors, and constructing a message passing graph in which each of a multiplicity of layers corresponds to a respective one in the sequence of images. The method also includes tracking multiple features through the sequence of images, including passing messages in a forward direction and a backward direction through the message passing graph to share information across time.

Abstract: A circuit for quenching an avalanche photodiode (APD) detector is disclosed herein. The circuit may comprise a discrete transistor configured to draw a quench current so as to enable a drop in a reverse bias voltage applied to the APD detector, and an integrated circuit connected to the discrete transistor, the integrated circuit including a plurality of circuit elements for controlling the reverse bias voltage.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan at least a portion of the emitted pulses of light along a scan pattern contained within an adjustable field of regard. The scanner includes a first scanning mirror configured to scan the portion of the emitted pulses of light substantially parallel to a first scan axis to produce multiple scan lines of the scan pattern, where each scan line is oriented substantially parallel to the first scan axis. The scanner also includes a second scanning mirror configured to distribute the scan lines along a second scan axis that is substantially orthogonal to the first scan axis, where the scan lines are distributed within the adjustable field of regard according to an adjustable second-axis scan profile.

Abstract: To dynamically control power in a lidar system, a controller identifies a triggering event and provides a control signal to a light source in the lidar system adjusting the power of light pulses provided by the light pulse. Triggering events may include exceeding a threshold speed, being within a threshold distance of a person or other object, an atmospheric condition, etc. In some scenarios, the power is adjusted to address eye-safety concerns.

Abstract: A system operating in a vehicle includes a lidar module, a camera, and a controller communicatively coupled to the camera and the lidar module. The lidar module includes: a light source configured to emit pulses of light, a scanner configured to direct the emitted pulses of light in accordance with a scan pattern to illuminate a field of regard of the lidar module, and a receiver configured to detect the emitted pulses of light scattered by one or more remote objects to capture a set of lidar pixels of a scan frame, in a sequence defined by the scan pattern. The camera has a field of view that at least partially overlaps the field of regard of the lidar module. The controller is configured to cause the camera to capture multiple images while the receiver of the lidar module captures the set of lidar pixels of the scan frame.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan the emitted pulses of light along a high-resolution scan pattern located within a field of regard of the lidar system. The scanner includes one or more scan mirrors configured to (i) scan the emitted pulses of light along a first scan axis to produce multiple scan lines of the high-resolution scan pattern, where each scan line is associated with multiple pixels, each pixel corresponding to one of the emitted pulses of light and (ii) distribute the scan lines of the high-resolution scan pattern along a second scan axis. The high-resolution scan pattern includes one or more of: interlaced scan lines and interlaced pixels.

Abstract: A lidar system includes a light source configured to emit light pulses and a receiver configured to detect light from some of the light pulses scattered by remote targets. The receiver includes an avalanche photodiode operating in the linear mode for detecting the light pulses. To prevent damage to the linear mode avalanche photodiode a quench circuit is coupled to the avalanche photodiode, where the quench circuit reduces a bias voltage applied to the avalanche photodiode, when an avalanche event occurs at the avalanche photodiode.

Abstract: In one embodiment, a lidar system includes a light source configured to emit an optical signal and a receiver that includes one or more detectors configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system also includes a photonic integrated circuit (PIC) that includes an input optical element configured to receive the portion of the scattered optical signal and couple the portion of the scattered optical signal into an input optical waveguide. The input optical waveguide is one of one or more optical waveguides of the PIC configured to convey the portion of the scattered optical signal to the one or more detectors of the receiver. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Abstract: A light-based detection system includes a light source configured to emit light as a series of one or more light pulses, a transmitter configured to direct the one or more light pulses toward a remote target located a distance from the system, a receiver configured to detect a light pulse scattered by the remote target, and a controller. The pulses are at a wavelength between approximately 1400 nanometers and approximately 1600 nanometers, with pulse duration between 10 picoseconds and 20 nanoseconds and a pulse energy less than 2 microjoules. The controller is configured to determine the distance from the system to the target based on a time of flight for the detected light pulse, detect a fault condition indicating that the distance to the target is less than a threshold distance, and shut down the light source in response to detecting the fault condition.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan the emitted pulses of light across a field of regard of the lidar system. The lidar system also includes a receiver configured to detect a portion of the emitted pulses of light scattered by a target located a distance from the lidar system. The receiver includes an aluminum-indium-arsenide-antimonide (AlInAsSb) avalanche photodiode (APD) configured to: receive a pulse of light of the portion of the emitted pulses of light scattered by the target and produce an electrical-current pulse corresponding to the received pulse of light. The lidar system further includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for the received pulse of light.

Abstract: A lidar system operating in a vehicle comprising a first eye configured to scan a first field of regard and a second eye configured to scan a second field of regard. Each of the first eye and the second eye includes a respective optical element configured to output a beam of light, a respective scan mirror configured to scan the beam of light along a vertical dimension of the respective field of regard, and a respective receiver configured to detect scattered light from the beam of light. The field of regard of the lidar system includes the first field of regard and the second field of regard, combined along a horizontal dimension of the first field of regard and the second field of regard.

Abstract: A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.

Abstract: To clear the line-of-sight (LOS) on a window in a lidar system within a vehicle, ultrasonic transducers are physically attached to the interior surface of the window to remove debris. When debris is detected at the window, the ultrasonic transducers are directed to vibrate at an ultrasonic frequency thereby generating an ultrasonic wave which causes the debris to bounce off the window. In some scenarios, the ultrasonic transducers vibrate with a particular phase shift to generate a travelling wave that causes the debris to sweep across the window. Additionally, windshield wipers, spray from a nozzle, and/or a hydrophobic or oleophobic coating may be used in combination with the ultrasonic transducers to remove the debris from the window.